Elastic column base joint based on steel structure exposed column base

Abstract

The utility model relates to the technical field of building steel structure transformation, and discloses an elastic column base joint based on a steel structure exposed column base. The elastic column base joint comprises a steel column, anchor bolts, a disc spring set, a disc spring lower square base plate, a disc spring upper square base plate, double nuts, a concrete foundation, an embedded steel plate and shear-resistant steel bars. One end of the anchor bolt penetrates through the bottom plate to be connected with the concrete foundation, the other end of the anchor bolt sequentially penetrates through the steel column, the disc spring lower square base plate, the disc spring set and the disc spring upper square base plate to be connected with the double nuts, the two ends of the disc spring set abut against the disc spring lower square base plate and the disc spring upper square base plate respectively, and the bottom of the embedded steel plate is connected with the concrete foundation. The shear reinforcements are welded to the tops of the embedded steel plates, and the steel columns are limited to the shear reinforcements. The utility model can solve the problems of overlarge internal force, difficulty in transformation and repair, complicated construction and high potential safety hazard possibility of a large number of light steel structure building column foot parts, and has the advantages of reasonable mechanical property and convenience in installation.

Description

Technical Field

[0001] This utility model relates to the technical field of steel structure renovation in buildings, and in particular to an elastic column base node based on exposed column bases of steel structures. Background Technology

[0002] Column base joints play a crucial role in steel structure buildings. Their function is to effectively transfer the internal forces at the base of the steel column to the foundation, ensuring a stable and reliable connection between the steel column and the foundation. In practical engineering, column bases can be classified into exposed, enclosed, embedded, and inserted types according to their structural form. Among them, exposed column bases generally consist of a base plate, anchor bolts, stiffening ribs, and shear keys. They are simple in construction, easy to install, and allow for faster column base positioning and shorter construction cycles. Therefore, they are widely used in some single-story steel structure buildings, multi-story steel structure buildings with less stringent seismic requirements, and some lightweight steel structure buildings.

[0003] Currently, many steel structure buildings in China are quite old, and their functions are gradually becoming inadequate for current needs. Therefore, many steel structure buildings, such as steel frames, have a strong demand for renovation. During these renovations, the superstructure is usually modified, while the foundation cannot be altered. This creates a problem: modifications to the superstructure may increase the load, resulting in larger bending moments at the column bases. The inability to modify the foundation means that the original foundation design may be insufficient to withstand the larger bending moments transmitted from the column bases.

[0004] Exposed column bases can be designed as either hinged or rigid joints. In practical engineering, steel structure buildings using exposed column bases often design the column bases as rigid joints. Rigid joints provide the column base with greater stiffness, better structural constraint redundancy, and less deformation, which is beneficial to the overall structure. However, compared to hinged joints, rigid joints allow the column base to bear more bending moments. Therefore, the solution to the practical problems in the above-mentioned renovation projects lies in modifying the column base to reduce the bending moment it bears. This reduces the bending moment transmitted from the column base to the foundation, preventing it from exceeding the foundation's bending capacity.

[0005] In summary, to address the aforementioned issues, transforming the original rigid connection of this type of exposed steel column base into a semi-rigid connection is a more reasonable solution. This reduces the rotational stiffness of the column base, altering the distribution of internal forces within the structure and thus reducing the bending moment borne by the column base. Currently, there is considerable research on semi-rigid joints, many of which combine energy dissipation and resetting functions. However, existing semi-rigid joints primarily focus on seismic energy dissipation, leading to complex construction, cumbersome installation, large space requirements, and high costs. This affects their engineering practicality and makes them unsuitable for most current modifications of such column bases. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an elastic column base node based on exposed steel column bases.

[0007] The objective of this utility model is achieved through the following technical solution: An elastic column base node based on an exposed steel structure column base includes a steel column, anchor bolts, a disc spring assembly, a lower square pad of the disc spring, an upper square pad of the disc spring, double nuts, a concrete foundation, an embedded steel plate, and shear reinforcement. One end of the anchor bolt passes through the base plate and connects to the concrete foundation. The other end of the anchor bolt passes through the steel column, the lower square pad of the disc spring, the disc spring assembly, the upper square pad of the disc spring, and the double nuts in sequence. Both ends of the disc spring assembly abut against the lower square pad of the disc spring and the upper square pad of the disc spring, respectively. The bottom of the embedded steel plate is connected to the concrete foundation. The shear reinforcement is welded to the top of the embedded steel plate. The steel column is confined within the shear reinforcement.

[0008] A better option is that the double nut includes a fastening nut and a locking nut, with the two ends of the fastening nut abutting against the locking nut and the square washer on the disc spring, respectively, and the anchor bolt passing through the fastening nut and the locking nut.

[0009] A better option is that both the fastening nut and the anti-reverse nut are welded to the anchor bolt.

[0010] A better option is that the steel column includes an upright and a base plate, the bottom of the upright is fixedly connected to the base plate, the anchor bolt passes through the base plate and is located around the upright, the square pad under the disc spring is fixedly connected to the base plate, and the base plate is confined to the shear reinforcement.

[0011] A better option also includes longitudinal short stiffening ribs, column base stiffening ribs, and boot beams, wherein the boot beams are fixedly connected to the connection between the column and the base plate, the boot beams are connected to the base plate through the column base stiffening ribs, and the boot beams are connected to the column through the longitudinal short stiffening ribs.

[0012] A better option is to weld the boot beam to the base plate.

[0013] A better option is that the cross-section of the column is square or I-shaped.

[0014] A better option is that the embedded steel plate is embedded in the concrete foundation, with the top of the embedded steel plate flush with the top of the concrete foundation.

[0015] This utility model has the following advantages and beneficial effects compared to the prior art:

[0016] This utility model's elastic column base node possesses good rotational capability while retaining a certain capacity to withstand bending moments, making it a semi-rigid node. When the column base node bears a large bending moment, it can release a portion of the bending moment transmitted from the superstructure, redistributing internal forces to achieve the target structural state and protect the column base and foundation from damage. The design of the elastic column base node is flexible; after determining the base plate dimensions and anchor bolt arrangement, the required rotation angle, rotational stiffness, and bending bearing capacity can be achieved by flexibly changing the arrangement and number of disc spring assemblies. Since the disc spring assembly is composed of individual disc springs, the stiffness can be flexibly set. When the disc springs are aligned, the compressible displacement of the disc spring assembly increases, and the stiffness decreases; when the disc springs are stacked, the stiffness of the disc spring assembly increases. The elastic column base node is quick to install and convenient to construct. Unlike some existing semi-rigid nodes, this column base node does not require prestressing tensioning and has a simple structure. On the one hand, compared with other complex semi-rigid joints, this elastic column base joint can achieve a more ideal effect; on the other hand, it greatly reduces the difficulty of design and the complexity of construction, lowers costs, and simplifies the modification process while ensuring the effect. All of the above makes the engineering practicality of this elastic column base joint much greater than that of previous semi-rigid column base joints. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an elastic column base node based on an exposed column base of a steel structure according to this utility model;

[0018] Figure 2 This is a side view of an elastic column base node based on an exposed column base of a steel structure according to this utility model;

[0019] Figure 3 This is a front view of an elastic column base node based on an exposed column base of a steel structure according to this utility model;

[0020] Figure 4 This is a top view of an elastic column base node based on an exposed column base of a steel structure according to this utility model;

[0021] Figure 5 This is a schematic diagram of a disc spring assembly for an elastic column base node based on an exposed column base of a steel structure, according to this utility model.

[0022] Figure 6 This is a schematic diagram of a fastening nut and a locking nut for an elastic column base node based on an exposed column base of a steel structure, according to this utility model.

[0023] The components in the attached diagram are labeled as follows: 1-Column; 2-Base plate; 3-Anchor bolt; 4-Disc spring assembly; 5-Square pad below the disc spring; 6-Square pad above the disc spring; 7-Fastening nut; 8-Isolation nut; 9-Boot beam; 10-Longitudinal short stiffening rib; 11-Column base stiffening rib; 12-Concrete foundation; 13-Embedded steel plate; 14-Shear reinforcement. Detailed Implementation

[0024] The utility model objective of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the implementation of this utility model is not limited to the following embodiments.

[0025] Example 1

[0026] like Figures 1-6 As shown, an elastic column base node based on an exposed steel column base includes a steel column, eight anchor bolts 3, eight sets of disc springs 4, eight square pads under the disc springs 5, eight square pads on the disc springs 6, eight sets of double nuts, a concrete foundation 12, a pre-embedded steel plate 13, four shear reinforcement bars 14, two longitudinal short stiffening ribs 10, six column base stiffening ribs 11, and two boot beams 9; wherein, each set of double nuts includes a fastening nut 7 and a locking nut 8; the steel column includes a column 1 and a base plate 2. The pre-embedded steel plate 13 is pre-embedded in the top center of the concrete foundation 12, and the top of the pre-embedded steel plate 13 is flush with the top of the concrete foundation 12. The base plate 2 is set in the top center of the pre-embedded steel plate 13, and the four shear reinforcement bars 14 are all welded to the top of the pre-embedded steel plate 13. The four shear reinforcement bars 14 are located on the four sides of the base plate 2 and limit the position of the base plate 2. The top center of the base plate 2 is welded to the lower end of the column 1. The inner sides of two shoe beams 9 are welded to the front and rear sides of the column 1, and the bottom edges of the two shoe beams 9 are welded to the base plate 2. Each side of the column 1 is welded to one of the two shoe beams 9 via a longitudinal short stiffening rib 10, and the bottom of the two longitudinal short stiffening ribs 10 is welded to the base plate 2. The outer sides of the two shoe beams 9 are welded to the sides of six column base stiffening ribs 11, and the bottom edges of the six column base stiffening ribs 11 are welded to the top of the base plate 2. The two shoe beams 9 and the six column base stiffening ribs 11 divide the column 1 into ten bending-resistant zones. Each of the ten bending-resistant zones has a pre-drilled hole, and each pre-drilled hole is pierced by an anchor bolt 3. The lower end of anchor bolt 3 is fixed within the concrete foundation 12. The upper end of anchor bolt 3 passes sequentially through the embedded steel plate 13, base plate 2, lower square pad 5 of disc spring, disc spring assembly 4, upper square pad 6 of disc spring, fastening nut 7, and anti-reverse nut 8. The top of base plate 2 and the bottom of lower square pad 5 of disc spring are welded together. Disc spring assembly 4 abuts against lower square pad 5 and upper square pad 6 of disc spring, respectively. The bottom of fastening nut 7 abuts against upper square pad 6 of disc spring, and the top of fastening nut 7 is welded to the bottom of anti-reverse nut 8. Both anti-reverse nut 8 and fastening nut 7 are welded to anchor bolt 3.

[0027] Anchor bolts 3 are used to achieve a semi-rigid connection between the base plate 2 and the embedded steel plate 13. The disc springs of the disc spring assembly 4 are arranged in a stacked, paired, or mixed manner. The specific number and arrangement of the disc springs are determined by the load-bearing capacity and stiffness requirements of the disc spring assembly 4, which are determined by the specific bending resistance of the column base. Whether it is in a compressed state, and the amount of compression in the compressed state, needs to be determined by the initial rotational load required by the column base, the dimensions of the base plate 2, and the arrangement of the anchor bolts 3. When the initial disc spring assembly 4 is in a compressed state, it will generate a preload on the anchor bolts 3, thereby increasing the initial rotational torque of the column base. The square pad 5 under the disc spring increases the contact area of ​​the disc spring assembly 4, better realizing the pressure transmission between the disc spring assembly 4 and the base plate 2. The square pad 6 on top of the disc spring better realizes the transmission of the compression of the disc spring assembly 4 and the pull-out force of the anchor bolts 3. The concrete foundation 12 provides load-bearing support for the column 1. Shear reinforcement 14 is used to bear part of the shear force transmitted from column 1, and also to prevent column base slippage under excessive shear force. Longitudinal short stiffeners 10 are a measure for columns 1 with an I-shaped cross-section. Because the I-shaped cross-section of column 1 is an open cross-section, their function is to further enhance the out-of-plane stiffness of the base plate and further divide the base plate into smaller plates. Both ultimately aim to give the base plate 2 sufficient rigidity, reduce its out-of-plane deformation, and allow the entire column base to rotate in tandem. Column base stiffeners 11 and base plate 9 strengthen the connection between column 1 and base plate 2, while also increasing the out-of-plane stiffness of base plate 2 and reducing its out-of-plane deformation, allowing the two to move in tandem. Rotation of column 1 drives rotation of base plate 2, and base plate 2 transfers the resistance generated by the deformation of the disc springs to column 1 to resist the load transmitted from above. Tighten the fastening nut 7 until the disc spring assembly 4 reaches the required compression state. The lock nut 8 prevents the fastening nut 7 from slowly loosening under long-term stress, thus preventing a reliable connection from being formed. The column 1 has an I-shaped cross-section and mainly serves a supporting function. The base plate 2 increases the contact area at the bottom of the column 1.

[0028] The working principle of the elastic column base joint: When the column base bears a large bending moment, it tends to rotate. The base plate 2 compresses the disc spring assembly 4 upwards, causing the column base to rotate. At this time, the overall structure changes, the internal forces are redistributed, and the bending moment borne by the column base decreases. However, the bending moment borne by the column base is still greater than the bending moment generated by the compression of the disc spring assembly 4. Therefore, the column base continues to rotate until the bending moment generated by the compression of the disc spring assembly 4 is the same as the bending moment distributed to the elasticity by the upper structure, thus reducing the bending moment borne by the column base and effectively solving the problem of insufficient bending bearing capacity of the column base and foundation during the renovation process. An elastic column base joint based on exposed steel structure column bases can solve the problems of excessive internal forces, difficult renovation and repair, cumbersome construction, and easy safety hazards in the column base of many lightweight steel structure buildings. It has the advantages of reasonable mechanical properties and convenient installation.

[0029] Example 2

[0030] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0031] In this embodiment, the use of two longitudinal short stiffening ribs 10 is reduced, which lowers production costs and simplifies the process; the cross-section of the column 1 is square, and the square cross-section of the column 1 is a closed section. The column 1 constrains the deformation of the boot beam 9, so there is no need to add additional longitudinal short stiffening ribs 10.

[0032] The above-described specific embodiments are preferred embodiments of this utility model and are not intended to limit this utility model. Any other changes or equivalent substitutions made without departing from the technical solution of this utility model are included within the protection scope of this utility model.

Claims

1. An elastic column base joint based on an exposed steel structure column base, characterized in that: The steel column, anchor bolt (3), disc spring group (4), disc spring lower square pad (5), disc spring upper square pad (6), double nut, concrete foundation (12), embedded steel plate (13) and shear reinforcement (14), one end of the anchor bolt (3) is connected with the concrete foundation (12) through the bottom plate (2), the other end of the anchor bolt (3) is connected in turn through the steel column, the disc spring lower square pad (5), the disc spring group (4), the disc spring upper square pad (6) and the double nut, the two ends of the disc spring group (4) are respectively abutted with the disc spring lower square pad (5) and the disc spring upper square pad (6), the bottom of the embedded steel plate (13) is connected with the concrete foundation (12), the shear reinforcement (14) is welded with the top of the embedded steel plate (13), and the steel column is limited in the shear reinforcement (14).

2. The elastic column base joint based on the exposed column base of steel structure according to claim 1, characterized in that: The double nut includes a fastening nut (7) and a stop nut (8), the two ends of the fastening nut (7) are respectively abutted with the stop nut (8) and the disc spring upper square pad (6), and the anchor bolt (3) passes through the fastening nut (7) and the stop nut (8).

3. The elastic column base joint based on the exposed column base of steel structure according to claim 2, characterized in that: The fastening nut (7) and the stop nut (8) are welded with the anchor bolt (3).

4. The elastic column base joint based on the exposed column base of steel structure according to claim 1, characterized in that: The steel column includes a column (1) and a bottom plate (2), the bottom of the column (1) is fixedly connected with the bottom plate (2), the anchor bolt (3) passes through the bottom plate (2), the anchor bolt (3) is located around the column (1), the disc spring lower square pad (5) is fixedly connected with the bottom plate (2), and the bottom plate (2) is limited in the shear reinforcement (14).

5. The elastic column base joint based on the exposed column base of steel structure according to claim 4, characterized in that: It also includes a longitudinal short stiffening rib (10), a column foot stiffening rib (11) and a shoe beam (9), the shoe beam (9) is fixedly connected at the connection between the column (1) and the bottom plate (2), the shoe beam (9) is connected with the bottom plate (2) through the column foot stiffening rib (11), and the shoe beam (9) is connected with the column (1) through the longitudinal short stiffening rib (10).

6. The elastic column base joint based on the exposed column base of steel structure according to claim 5, characterized in that: The shoe beam (9) is welded with the bottom plate (2).

7. The elastic column base joint based on the exposed column base of steel structure according to claim 4, characterized in that: The cross section of the column (1) is square or H-shaped.

8. The elastic column base joint based on the exposed column base of steel structure according to claim 1, characterized in that: The embedded steel plate (13) is embedded in the concrete foundation (12), and the top of the embedded steel plate (13) is flush with the top of the concrete foundation (12).

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